Both sliding and pivotally mounted doors are provided with a lock having a tongue, with the tongue being adapted to engage a striker to retain the door in the closed position. The striker is attached to the door jamb.
For the lock tongue to correctly engage the striker, there needs to be an accurate location of the striker and lock. Obtaining this correct location it is often time consuming and difficult. This is particularly evident in sliding doors where the doors are adjustably mounted on rollers.